As part of the preparatory works for the lengthening of platforms 1-4 at Waterloo, a new gantry has been erected across the ends of platforms 1-8. On platform 8, this gantry carries a new signal - already in use - about a coach length in from the platform end (ie, towards the concourse), so that the front of a 10-coach (444) or 12-coach (450) train is beyond it. This signal is numbered W15. At the very end of the platform, the original 'starting' signal is still in use, now numbered W15CA. I understand the CA suffix to indicate 'co-actor', but if this is the case aren't these signals the wrong way round? Shouldn't the 'main' signal be right at the end of the platform, with the co-actor further back, perhaps for easier sighting from shorter trains?

A visit to Waterloo platform 8 revealed what might be going on with signal W15. A new gantry has been erected across platforms 1 to 7 with an additional small section cantilevered from the right side upright with the W15 3 aspect head and RI. As platforms 1 to7 are extended the platform signals will be added to the gantry. At present a 442 type of train, two units coupled together stands nearly two coaches past W15 signal. The original structure which has W15 CA fixed to it has a left side long cantilever with platform signals 6 and 7 fixed on it. It's an old signal cantilever and may well be in the way for remodelling. There was no alteration to the track circuits. The existing replacement track replaces W 15 CA and W 15 to Red when the train occupies the track circuit. The signal plates are correct. A train approaching a signal at red, the driver would expect to see the signal with an I.D. plate not with CA [co-actor] on it in the first instance. As platform 8 will be reduced in length if W15 CA is removed, it may be planned to renew the signal.